1. Field of the Invention
The invention relates to a circuit-breaker such as those used in power plants, transformer substations and other installations in the supply of electric energy for connecting and disconnecting operating currents and overcurrents.
2. Discussion of Background
EP-B-0 177 714 has disclosed a circuit-breaker of the generic type in which the pressure volume is connected to the exhaust only via the heating volume. Consequently, it is impossible for the pressure chamber to be directly relieved in the case of high current strengths. In order to avoid overpressures in the case of high current strengths, the pressure chamber and heating volume must therefore be appropriately designed so that the pressure buildup in the case of relatively low currents can make only a slight contribution to quenching the arc. In the case of known circuit-breakers of the generic type, the arcing chamber is therefore connected directly to the exhaust in order to avoid overpressures. A circuit-breaker of the same type of design has been disclosed in EP-A-0 456 139.
Although in the case of the circuit-breaker in accordance with DE-A-196 13 568, the arc is crossed by the gas flow and very effectively blown out, only some of the pressure built up by the heating of the gas by the arc is utilized for blowing out, with the result that most fields of use require an additional mechanical blowout device of comparatively large dimensions.